The conductance of s-acetylthiocholine halides and perchlorate has been measured in n- butanol at 25 ° C.The data were analyzed using the Fuoss=Onsager eq uation for 1:1 associated electrolytes and the characteristic function, Λ ÃƒÂ¢Ã‚â€”Ã‚Â¦ (equivalent conductance at infinite dilution), a ° (contact distance of approach) and K A (association constant) has been derived. The assoc iation constant K A was analyzed on the basis of the solvent separated -ion pair model.